Patents by Inventor Raimo Pitkanen

Raimo Pitkanen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5403442
    Abstract: A method for washing a fibrous suspension. The fibrous suspension is dearated with a deaerating centrifugal pump as it is pumped into the washing zone. The washing water is also dearated with a deaerating centrifugal pump.
    Type: Grant
    Filed: November 29, 1993
    Date of Patent: April 4, 1995
    Assignee: A. Ahlstrom A Corporation of Finland
    Inventors: Kaj Henricson, Raimo Pitkanen
  • Patent number: 5323914
    Abstract: A method and an apparatus for separating heavy impurities from a fiber suspension include a centrifugal pump capable of separating heavy impurities towards the periphery of the interior chamber of the pump. The fiber suspension is caused to rotate in the interior chamber so as to urge the suspension downstream as well as separate the impurities towards the periphery of the chamber where they can be collected.
    Type: Grant
    Filed: February 6, 1992
    Date of Patent: June 28, 1994
    Assignee: A. Ahlstrom Corporation
    Inventors: Kaj Henricson, Raimo Pitkanen, Pentti Vikio
  • Patent number: 5240621
    Abstract: A method of separating an aqueous solids containing suspension includes (a) subjecting a first solids containing suspension to centrifugal forces so as to separate the suspension into a first gas containing flow, a second gas-free flow and a third flow; (b) feeding the third flow into a flotation cell having a bottom; (c) introducing air at the bottom of the flotation cell into the third flow for separating from the third flow a fourth partial flow; (d) withdrawing the air containing third flow after the separation of the fourth partial flow from the flotation cell; and (e) subjecting the third flow to the centrifugal forces of step (a).
    Type: Grant
    Filed: July 29, 1991
    Date of Patent: August 31, 1993
    Assignee: A. Ahlstrom Corporation
    Inventors: Jorma Elonen, Harry Erlund, Kaj Henricson, Pasi Immonen, Raimo Kohonen, Heikki Manninen, Kari Peltonen, Raimo Pitkanen, Pentti Vikio
  • Patent number: 5234480
    Abstract: The invention relates to a method and assembly for decreasing problems, especially odor hazards and interference with pump action, caused by residual or reaction gases, evolved or picked up in gas washers and various other partial process apparatuses of a pulp process. Residual or reaction gases and/or gases harmful to the carrying out of a process or to the environment are separated from liquid or fiber pulp suspension by means of a deaerating pump which advances the flow of liquid or fiber pulp suspension, separates said gases from said liquid or fiber pulp and vents said gases to outside said process apparatus. The invention concerns in general the use of a deaerating pump for a variety of purposes in the pulp and paper industry for eliminating gas problems.
    Type: Grant
    Filed: July 29, 1991
    Date of Patent: August 10, 1993
    Assignee: A. Ahlstrom Corporation
    Inventors: Kaj Henricson, Raimo Pitkanen
  • Patent number: 5219472
    Abstract: A method and apparatus for improving the treatment of a gas containing fiber suspension in the pulp and paper industry, especially for increasing the capacity of a screening department, a washing department, a thickening department, a press, a curved screen, or the like, includes the simultaneous separation and removal of the gases prior to the respective treatment stage.
    Type: Grant
    Filed: July 29, 1991
    Date of Patent: June 15, 1993
    Assignee: A. Ahlstrom Corporation
    Inventors: Jorma Elonen, Kaj Henricson, Olavi Pikka, Raimo Pitkanen